This invention relates to sulfonamide intermediate compounds and processes of making same. The compounds are useful for synthesis of compounds which inhibit production of cytokines involved in inflammatory processes.
Tumor necrosis factor (TNF) and interleukin-1 (IL-1) are important biological entities collectively referred to as proinflammatory cytokines. These, along with several other related molecules, mediate the inflammatory response associated with the immunological recognition of infectious agents. The inflammatory response plays an important role in limiting and controlling pathogenic infections.
Compounds which modulate release of one or more of the aforementioned inflammatory cytokines can be useful in treating diseases associated with release of these cytokines. For example, WO 98/52558 discloses heteroaryl urea compounds which are indicated to be useful in treating cytokine mediated diseases. WO 99/23091 discloses another class of urea compounds which are useful as anti-inflammatory agents. WO 99/32463 relates to aryl ureas amd their use in treating cytokine diseases and proteolytic enzyme mediated disease. WO 00/41698 discloses aryl ureas said to be useful in treating p38 MAP kinase diseases.
U.S. Pat. No. 5,162,360 discloses N-substituted aryl-Nxe2x80x2-heterocyclic substituted urea compounds which are described as being useful for treating hypercholesterolemia and atheroclerosis.
U.S. Pat. No. 6,358,945 and U.S. application Ser. No. 09/834,797, now U.S. Pat. No. 6,608,052, describe heteroaryl urea compounds useful for treating cytokine mediated diseases. One of the general schemes for producing such compounds is found in Scheme I of U.S. Ser. No. 09/834,797: 
One of the formula IIa arylamine intermediates is a sulfonamide of the formula: 
5-tert-Butyl-3-methanesulfonamido-2-methoxyaniline.
Example 2 disclosed therein describes its synthesis, however the three step synthesis provides a less than desirable approximate 70% yield, 
Example 1 in the application demonstrates another route to obtain the reduced amine in step 1 above: 
Selective reduction of one nitro group in dinitroaryl compounds has been shown by Entwistle, et al. using cyclohexene for the transfer hydrogenation. Entwistle, I. D. et al. J. Chem. Soc., Perkin trans, 1, 1975, 1300. During this process benzene is formed as a byproduct which is a known carcinogen.
The present application provides an improved more economical process for synthesis of such intermediates by an increasing overall yield to approximately 81% and producing toluene rather than benzene, toluene being more environmentally safe.
It is an object of the invention to provide an improved sythesis for compounds of the formula (A): 
(A), such as 5-tert-Butyl-3-methanesulfonamido-2-methoxyaniline.